1. Field of the Invention
The present invention is directed to a circuit and method for triggering an over-voltage protection unit, the over-voltage protection unit being disposed in or on a module and being connected via at least one connection line between a signal input and a signal output of the module.
2. Description of the Prior Art
Over-voltage protection units are provided in modules, in particular subscriber terminal modules, in order to protect the active and passive elements of the module from destruction by interference voltages that are unavoidably fed in. These interference voltages can for example be high-voltage pulses (spikes) caused by lightning. Conventionally, a response of the over-voltage protection units on a module is tested with test voltage pulses from a pulse voltage generator. The evaluation of the test result takes place by subsequently conducting a functional test of the module, and, if warranted, evaluating signal curves recorded during the test voltage pulses at components of the module. This type of test for the response of the over-voltage protection unit, however, has the disadvantage that it is tedious and requires trained personnel for evaluation.